EP 2025515 A1 discloses a screen printing press having a printing assembly that comprises two printing points. Each printing point is formed by a screen cylinder thrown onto an impression cylinder. A drying unit that uses UV radiation is provided in the printing substrate path between the two printing points, and can be used for at least superficially drying the ink pattern that is applied in the first printing point. A ink pattern having printed areas that directly adjoin or even overlap with the areas first printed can then be applied in the second printing point. A plurality of image elements arranged in rows and columns and comprising these two areas are thereby printed onto one printing substrate sheet, for example.
EP 1648702 B1 discloses a printing press having a printing unit that operates according to the screen printing method, in which one printing cylinder or cylinder of a conveyor line has at least one magnetic element for aligning pigments contained in the ink, and the printing substrate path comprises a dryer located downstream.
EP 2067620 B1 concerns a method for drying printed material in multicolor printing, in which drying is performed by means of a one-dimensional or two-dimensional array of radiation sources, depending on the image content. In said method, data from the prepress stage are used for controlling the light sources individually or in groups.
DE 10 2009 007873 A1 discloses a sheet-fed printing press in which a sheet imprinted with UV-curable inks is acted on by exposing a predetermined area thereof to UV light. For this purpose, the apparatus comprises a plurality of LEDs, which are arranged in predetermined zones in the transverse direction of the sheet and are switched in accordance with the location and size of predetermined areas. Individual zones can be switched on in the transverse direction based upon the width of the area of the sheet that is passing through or based upon whether an image is contained in the zone in question.
In the direction of transport, zones can be switched on based upon the leading and trailing ends of an image or based upon the spacing of a plurality of partial images spaced from one another in the longitudinal direction. The area of exposure is calculated by a corresponding calculating unit, based on data that are provided prior to the printing process.
From DE 10 2012 215491 A1 a processing machine and a method for operating the same are known, in which data relating to the subject of a job are fed to a control console, and, taking these data into account, a control device for a dryer is supplied with signals, by means of which the dryer can be activated and deactivated zonally across the format width of the printing substrate, taking the subject into account.
EP 1599340 B1 concerns the ultraviolet curing of coating compositions, in which, by way of example, in an inkjet head oscillating laterally over a printing substrate, LEDs that are moved along with the head irradiate only printed target areas for the purpose of selective drying. Control is implemented, e.g. by means of software, for example using a raster image or some other system used in the production of the printed image. In a modified variant, control of the LEDs is
transferred to intermediate dryers or a final dryer of an offset printing press. Alternatively, this can also be applied to a screen printing technique, to enable the controlled drying of a printed substrate prior to a subsequent printing step.
EP 1439071 B1 concerns an inkjet printer which has a dryer that is controlled based upon a temperature or a humidity measured by a sensor.
US 2007/0206083 A1 also concerns an inkjet printer, in which the ink is cured by irradiation or some other application of energy. LEDs that are moved along with the inkjet head are used for the purpose of irradiation, with the quantity of radiation and the profile in the direction of paper transport being adjusted differently based upon the paper that is used.
DE 10 2007 040139 A1 discloses a printing press in which a dryer is positioned in a sheet-guiding drum, co-rotating therewith. The dryer can be controllable zonally in the circumferential direction and/or in the axial direction, independently of adjacent zones, and can thus be adaptable to the printed image. The zones, in a checkerboard pattern, for example, can be actuated based upon the printed image. The data for this can be taken from the prepress stage. Actuation can also be based upon operating parameters, including printed sheet parameters such as the printed sheet format.
EP 1142711 A1 discloses a controller for the dryer device of a printing press, in which the dryer device is controlled based upon variables that characterize the printing process. As one such variable, the radiation output of a UV or IR dryer can be controllable based upon the ink coverage of a printing unit upstream. In cases in which dryer devices are arranged distributed in blocks over the format width, the individual blocks can also be actuated in accordance with the ink coverage of the subject. The data concerning ink coverage to be used for this purpose can be obtained by scanning the printing plate, or preferably in the form of a data set from the digital prepress stage.
EP 2025515 A1 discloses a security printing press having two screen printing units, with one UV dryer positioned therebetween. The screen printing units can be used for applying image elements for each copy, according to a grid composed of multiple columns and rows of copies.
WO 2015/118447 A2 discloses a security printing press having a printing unit that operates according to the letterset process, and an additional screen printing unit. The printing unit that operates according to the letterset printing process can be used in its embodiment as a numbering printing unit, for example, for applying serial numbers to the copies.
EP 0949069 B1 discloses a security printing press with which, at a first printing point, a first side can be imprinted in two colors, and in a second printing point, both sides can be imprinted simultaneously in multiple colors. A UV dryer is located between the two printing points and is directed toward the side that has just been imprinted.
From EP 1466731 A1, a method and a device for drying ink on a printing substrate are known, in which an infrared absorber is applied to the printing substrate, and the printing substrate is exposed downstream to appropriately narrow-band radiation. In a refinement, the printing substrate can be acted on by a field of individual radiation sources, which are actuated such that the amount of energy input is based on the volume of printing ink previously applied.